This invention relates to access control, and more particularly it is concerned with a high security access control system involving credit card type keys or mechanical keys and locks as well as keyholder authentication to prevent unauthorized use of a key.
A number of different types of access control systems and devices have existed in use or in previous patents--for example, the systems of National Computer Systems, Inc. and Continental Instruments, Inc.
Cylinders and keys having mechanical configuration in combination with electrical, magnetic or optical locking or unlocking devices have also been known. See, for example, U.S. Pat. Nos. 4,603,564, 4,658,105, 4,633,687, 4,458,512, and 3,733,862. In some of these devices, keys and cylinders could be coded by the manufacturer or by the user, with the non-mechanical aspect of the key affording additional security against opening of a lock without the proper key. In these combinations of mechanical and non-mechanical security features on a key, the non-mechanical code or configuration or pattern simply added to what was required to open the lock, generally not carrying other readable data useful for other purposes.
U.S. Pat. No. 4,537,484 shows one example of a fingerprint reader system for use in identity verification. Another such reader is manufactured by ThumbScan, Inc. of Oakbrook Terrace, Ill., for the purpose of computer terminal security. Such scanners have also been suggested for use in identification in access control systems involving granting of entry only to authorized persons. However, these systems have not cooperated with keys and locks which could be used in the same facility. Also, they have generally required processing of the attempted user's fingerprint in a central processor which would have to either compare the attempted user's fingerprint with hundreds or thousands of stored fingerprints in a database, or would receive a user identification number keypunched in by the person seeking access, and then look up a database-stored fingerprint corresponding to that code and make the comparison. Such a central look-up and comparison would involve a great deal of central computer memory and power, and the use of many-conductor bus cables between each access control point and the central processor, and would tend to require considerable time or a very high powered computer, to complete the access control decision. This equipment and installation of the cables can involve great cost, particularly when added to an existing building.
A different approach to access control decision making is taken by the present invention described below. In a preferred embodiment, a keyholder carries a key which not only has a mechanical configuration for accessing mechanical locks (or a card type key with non-mechanical lock access features), but also carries encoded data representing a personal identifying code or feature of the keyholder, as well as a simple identity number or code. The high security authentication comparison can be made directly at the access control point, by a small processor board located behind a reader panel.